1. Field of the Invention
This invention relates to an electricity-light transmitting composite wire for transmitting both electrical energy and optical signals.
2. Description of the Prior Art
Heretofore, in the field of power transmission, composite of optical fiber and electric wire have been used. In a typical construction, an optical fiber unit formed by gathering a suitable number of optical fibers is positioned at the center and a plurality of metal strands are twisted together around such optical fiber unit.
At present, such composites of optical fiber and electric wire are limited in use to the field of power transmission. It seems that the reason is that composite wires having optical fiber and electric wire compounded together are highly rigid and hence hard to handle and are not so compact in form. Therefore, in the field of power distribution including connection between two parts, they cannot be used as such.
As is known in the art, optical fiber has the merit of being capable of transmitting an extremely high density optical signal despite the fact that it is compact in form. In contrast, in the case of electric wire, when it is desired to transmit high electric energy or to transmit electrical signals or the like over a long distance without suffering much attenuation, it is necessary to correspondingly increase the cross-sectional area of the electric wire. Therefore, in a composite wire of optical fiber and electric wire, if a compact form is to be attained, this involves a reduction in the cross-sectional area of the wire section, entailing a reduction in the amount of electric energy which can be transmitted or attenuation of electric signals to be transmitted.